Digest auth error

[Shaolin]

Hi Guys

I am trying to setup Digest authorization for one of my virtual hosts. The problem is when I try to start apache I get the following error:

Invalid command 'AuthDigestDomain', perhaps misspelled or defined by a module not included in the server configuration

Below is my configuration in the vhosts conf file:

NameVirtualHost 127.0.0.1
<VirtualHost 127.0.0.1>
   DocumentRoot /www/sites/site1
   ServerName www10.site.local
      <Location /sites/>
            AuthType Digest
            AuthName MySite
            AuthDigestDomain http://www10.site.local
            AuthDigestProvider file
            AuthUserFile /usr/auth/.digest_pw
            Require valid-user
      </Location>
</VirtualHost>

Does anyone know where I am going wrong? I am running the latest version of apache.